Positive-position timing clutch



March 11, 1930. A. R. MASON 1,750,115

POSITIVE POSITION TIMING CLUTCH Filed NOV 24, 1923 mm|mllllllllllllllluqfi Patented Mar. 11, 1930 PATENT OFFICE ARTHUR LR. MASON, F MEDFORD, OREGON POSITIVE-YOSITION TIMING CLUTCH Application filed November 24, 1928.

My invention has for its object means actuating a mechanical moving part to return the same to a positive position after a movement in excess thereof.

Another object is means adapted to positively position a mechanical part which has been moved to excess by reversing the move ment to a predetermined position.

Another object is in mechanism of the character described, a friction clutch introducing a relatively constant drag upon the ad vancing movement of a mechanical part and returning the part to a predetermined position after a movement in excess thereof.

A further object is a mechanism of the character described including pawl and ratchet means whereby, upon termination of any relative fractional movement in one direction the drag clutch returns the ratchettooth against the pawl as a stop thus securing a definite predetermined position for the moving part.

Other objects will appear from the drawings and specifications which follow.

By referring to the accompanying drawing and description, my invention will be made clear.

In the drawing, Fig. 1 is a cross section of a mechanism employing one form of my invention.

Fig. 2 is a fragmentary end view of a portion of Fig. 1 with certain of the parts omitted and other parts shown in section on the line 11-11 thereof.

Fig. 3 is a detail of the pawl and ratchet of Fig. 2 showing a relative displacement at the termination of a first movement involving a fraction of one of the ratchet teeth and before the clutch has returned the ratchet against the pawl as shown in the later position of Fig. 2.

Fig. i is an end view with certain of the parts removed to illustrate the action of the clutch.

1' Fig. 5 is a fragmentary plan view of an Serial No. 321,652.

upper portion of the member 12, showing the action of the plurality of pawls 10.

Throughout the figures similar numerals refer to identical parts.

My invention is particularly applicable to gasoline recording mechanism and the like, such as that fully set forth in my co-pending applications: No. 288,711, filed June 27, 1928; No. 294,874, filed July 23, 1928; No. 29%,875, filed July 23, 1928; and to which reference is herein made.

Referring to the drawings, numeral 1 indicate a stationary shaft mounted upon an instrument casing shown in fragment by the numeral 2.

On the shaft 1, is 'rotatably mounted the member 3, carrying the drum 4 adapted to ad- Vance a conventional paper strip.

A gear 5 mounted on the shaft 1 is adapted to be rotated from the pinion 6 carried on the shaft 7 which also carries pinion 8 meshing with the pump rack 9, as for example a conventional rack of a gasoline feed pump.

The gear 5 drives the member 3 and drum i through the pawls 10 which engage with the skew teeth 11 carried on the cylindrical member 12, all as set forth in my above copending applications, and by the action recited a paper strip is advanced by the drum 1 in proportion to the gasoline fed by the pump whose rack is 9.

The member 12 is also provided with the ratchet teeth 13 and these teeth are engaged by the pawl 14 fixed on the lug 15 of the easing 2, so that while the member 12 is permitted to advance in the direction of the arrow 16, it is held by the pawl 14; which engages against the face of any of the teeth 13 upon a reversal of movement in the direction of the arrow 17-see Figs. 2 and 3.

At 20 is a disc having a friction face and fixed to rotate with the members 3 and 12.

At 21 is a similar disc fixed to rotate but free to make an axial movement towards the disc 20 under the action of a plurality of compression springs one of which is shown at 22.

The tension of these springs is adjustable by the screws as 23, the rotation of which, in the member 3, shifts the position of the nut 24 and therefore the spring compression against the plate 21 is correspondingly varied.

In operation these plates bind between them due to the compression of the springs 22, a third frictional member indicated at 25 and which is here shown in disc form having the centering shoulder 26 concentric with the inner diameter of the disc 21.

The shoulder 26 retains the disc 25 con centric with the shaft 1 with its outer portion in frictional engagement between the plates 20 and 21.

Coil springs at 30. 31 respectively fixed at one end to the disc 25 and at their other ends with the shaft 1, restrain the disc from ro tating an excessive distance in the direction of the arrow 16.

It will now be seen that as the gear 5 through the pawls 10 and teeth 11, drives positively the member 3 and the latter carries with it the disc 25 through frictional engagement between plates 20, 21 and 25 until the springs 30, 31 exert suflicient tension to cause the disc 25 to slip and at such time the springs will remain in tension as long as the rotation continues in the direction of the arrow 16.

However, if there is any reversal of movement in the gear 5 the tension of the springs 30, 31 functioning through the friction discs will cause the member 3 to reverse its move ment, until, and only until the pawl 14 engages the face of one of the teeth 13.

In other words reversal of the movement of the drum 3 will continue only until a positive integral position has been reached which is an integral unit multiple of movement corresponding with the spacing of the teeth 13 and therefore of the member 3 and drum 4. Therefore any conventional mechanism connected therewith, or paper strip operated thereby will stop at a predetermined line corresponding with the engagement of the pawl 14 against the face of one of the teeth 13.

Thus when the pump rack 9 has been raised delivering for example gasoline from the pump, the gear 8 will have rotated and the gear 5 caused the movement in the di rection of the arrow 16 of the drum 4 during the entire delivering stroke of the pump. The rack 9 is now returned to its zero position to be ready for the next stroke of the pump, and during this return movement the gear 5 will rotate in the direction of the arrow 17 and during the first instant of said return movement in the direction 17, the drum 4 will have rotated also in the direction 17 until the pawl 14 has engaged against the tooth face 13 corresponding exactly with a unit division on the drum 4, or the paper strip which it operates, indicating the amount of the commodity delivered by the pump.

To calibrate the apparatus in accord with variations in different pumps so that it will register by movement of the drum 4 exactly in accord with the actual delivery of any pump for which the machine is constructed, I employ a lateral axial movement of the gear 5 such that as it is making its rotative movement in the direction of the arrow 16 it likewise moves axially in the direction of the arrow 40, through the ball member 41 fixed with the gear 5 and which ball tracks within the curved slot 43.

The degree of the lateral displacement of the gear 5 may be adjusted by the screws 45, 46 which bear upon an integral projection 47 carried by the track member 43, and which member is pivotally supported on the pin 48, carried in the shaft 1. Thus by advancing the screw 45 and relieving the screw 46 the degree of displacement of the gear 5 during said rotation will be increased one direction or by relieving the screw 45 and advancing the screw 46 the degree of displacement of the gear 5 during its rotation will be reduced.

At 49 it will be observedthat the track member is provided with an increased curvature which corresponds with the initial movement of the gear 5 when the pump rack 9 first begins to advance during a feeding operation by the pump and this momentarily increases the rate of lateral displacement of the gear 5 so that the ratchet teeth 10 will quickly engage upon the screw teeth 11 and also to compensate for such lost motion or W wear as may exist in the parts of the mechanism.

As the gear 5 rotates in the direction of the arrow 16 it is displaced from the initial extreme position 50 to the other extreme position 51, see Fig. 1, and upon the reverse movement in the direction of the arrow 17 it moves in the opposite axial direction from 51 to 50.

I claim: I

1. Positive position mechanism comprising a driven element and a stationary member, friction means and spring connections thereto between said element and said member, a plurality of ratchet teeth on said driven element and a pawl adapted to engage against any of said teeth under the action of said friction means and said s ring connections upon an interruption o the driving force.

2. Positive position mechanism comprising a shaft, a late, and spring connections between said plate and said shaft, a friction member elastically contacting with said.

plate, and pawl and ratchet means associated with said member and intermittent driving means for said member whereby upon the in terruption of any driving movement the ratchet returns against the pawl.

3. Positive position mechanism comprising a circular element having ratchet teeth, a stationary shaft about Which said element is adapted to be driven intermittently in one direction, a pair of discs Within said element, a friction plate between said discs, spring connections between said plate and said shaft, other springs means compressing said discs against said plate.

ARTHUR R. MASON. 

